Generally, speed of a head drum motor of a household VTR is set to 1,800 rpm and further, the tape running speed becomes 33 mm per second. A running length of a tape which is sloped towards a direction of rotation of the head drum is 33 mm/30 rounds=1.1 mm/round because the drum rotates at a speed of 30 rounds per second. A track that is 58 .mu.m wide has a format as shown in FIG. 1 and a gradient of 6.degree. in the tape running direction. Accordingly, a tape length `L` of each track, in the tape running direction, is about 554.8 .mu.m from a formula L=58 .mu.m/Cos 84.degree.. Thus, a tape length of two tracks is 554.8 .mu.m.times.2=1100 .mu.m=1.1 mm because the head drum reads two tracks per round and this length is equal to the length inclined to a direction of rotation of a head.
Because the head reads a tape from a lower end of a first track to an upper end of a second track when the tape is stopped as shown in FIG. 1, data of a central portion of the tracks may be lost and accordingly a noise bar appears on a central portion of a picture during the display of the picture of poor quality.
In a high speed search mode of operation, a tape running speed becomes fast, so that a tracking trace of the head drum will stand up with respect to a direction of the tape width and consequently the head is tracking three to four tracks per round. Accordingly, may appear three or four noise bars on the screen, resulting in a poor picture quality when reproducing.
For solving the above mentioned problems, there is introduced a method of automatic tracking for jumping over a track by actuating a capstan motor when reproducing a picture. However, it is difficult to embody the method because of the difficulties in controlling a servo.
In the high speed search mode of operation, it is, however, possible to search for a tape location quickly by utilizing an address code which indicates the tape location, recorded on a control track of a VTR tape.
As shown in FIG. 4, the address signal includes three identical address blocks, each block consisting of twenty seven bits. Further, the respective blocks have a header code of eleven bits and an address code of sixteen bits. Every bit is matched with a video track, and a head drum having two channels and four heads is used during recording. Herein, four tracks make one field and eight tracks make one frame. The three address blocks consist of eighty one tracks, which corresponds to the addresses for about ten frames.
The reason why one address signal includes the three identical address blocks as mentioned above is to solve the problem that the head drum is not able to read the address accurately due to the high tape speed during the high speed search mode of operation. However, a recent rapid development in electronic engineering makes it possible for the head drum to read the address efficiently even if the address includes only one address block. Therefore, it is uneconomical to record the same three address blocks in one address in consideration of utilizing the tape.